Amine alanes eg. AlH.sub.3 .multidot.NR.sub.3 and AlH.sub.3 .multidot.2NR.sub.3) are complexes of tertiary amines (NR.sub.3) with alane, i.e. aluminum hydride (AlH.sub.3) Amine alanes are used in various reduction processes, in the preparation of aluminum, and in the production of silane. See, for example, Marlett, U.S. Pat. No. 4,474,473, issued Oct. 2, 1984; and Brendel, U.S. Pat. No. 3,552,946, issued Jan. 5, 1971.
The production of amine alanes has been accomplished by several methods (see Nelson, Becker, and Kobetz, U.S. Pat. No. 3,651,064, issued Mar. 21, 1972, and references therein).
Dilts and Ashby, Inorg. Chem 9(4), 855 (1970), in a study of complex metal hydrides in tertiary amine solvents, found that trimethylamine extracted alane from lithium aluminum tetrahydride (LiAlH.sub.4, also referred to herein as "lithium aluminum hydride") to produce an amine alane, AlH.sub.3 .multidot.2N(CH.sub.3).sub.3.
Dilts and Ashby, in the same study, were unsuccessful in extracting alane from sodium aluminum tetrahydride (also referred to herein as "sodium aluminum hydride") by any amine.
Another route to amine alane is by the production of lithium aluminum hydride by the reaction of lithium chloride with sodium aluminum hydride, as taught by Robinson (French Patent 1,245,361; 1960), followed by extraction with dimethylethylami or N-methylpyrrolidine, as taught by Park and Marlett, J. Org. Chem., 55, 2968 (1990).
In one process for preparation of sodium aluminum hydride, aluminum and hydrogen react with trisodium aluminum hexahydride, Na.sub.3 AlH.sub.6, under pressure, as taught by Beaird and Kobetz, U.S. Pat. No. 3,355,262, issued Nov. 28, 1967.